当上行柱塞上的斜槽与柱塞套上的油孔相通时,柱塞式喷油泵()。
A.准备喷油
B.开始喷油
C.结束喷油
参考答案:C
_____ in time for Christmas,all these gifts must be mailed immediately
A.So as to be received
B.In order to receive
C.So as to be receiving
D.In order to be received
CFB锅炉启动前应有()mm床了层。
A.120—180
B.210—350
C.280—400
D.350—500